1. Field of the Invention
The present invention relates to a toner for developing a latent electrostatic image by electrophotography, electrostatic recording, electrostatic printing and the like, and a developer and image forming method using the toner.
2. Description of the Related Art
An image formation by electrophotography is generally performed by a succession of process, in which a latent electrostatic image is formed on a latent electrostatic image bearing member (hereinafter also referred to as “photoconductor”), the latent electrostatic image is developed by a developer containing a toner so as to form a visible image (toner image), and the visible image is transferred on a recording medium such as paper so as to be fix thereon, thereby obtaining a fixed image (U.S. Pat. No. 2,297,691). A full color image formation is, generally, to perform reproduction of colors using toners of four colors consisting of black, yellow, magenta and cyan, wherein each color is developed and a toner image in which toner layers are superimposed on a recording medium is heated and fixed at the same time, so as to obtain a full color image.
However, images by full color copiers cannot satisfy users who are used to see printed images and silver halide photographic images, and are demanded for improvement of quality image, in which high definition and high resolution close to photographs and printing are satisfied. Particularly, when cardboards are used, or high speed printing is performed, heat transfer upon fixing is not sufficient. Thus, it is hard to obtain an image having excellent fixability and high image quality, specifically less variation in glossiness, density and image clarity.
A low temperature fixing system, and a toner corresponds to the system are studied, so that a toner corresponds to the low temperature fixing system can be produced by lowering softening temperature of the toner. However, such toner is not preferable, because the heat resistant storage property thereof becomes poor. A toner is severely influenced by environments such as high temperature and high humidity, low temperature and low humidity or the like, during storage, and transportation after production of the toner. Even after stored in such environments, a toner having excellent storage property, in which toner particles are not aggregated, and charge property, flowability, transfer property and fixing property are not or less degraded, is demanded.
On the other hand, it has been understood that toner spent on a developing member, carrier and the like adversely affects charge property and developing property. A toner which can solve these problems and suitably satisfy low temperature fixability, heat resistant storage property and developing stability, and a developer and image forming apparatus using the toner have not been provided at the moment.